to approval be made; and (7) a check, draft, or money order, payable to the United States Bureau of Mines, to cover the fee for inspection and tests. The fee will be placed on special deposit in the Treasury of the United States, pending disposal as specified in this section. No supplied-air respirator will be accepted for permissibility tests unless it is substantially in the completed form in which it is to be marketed. Application for tests shall be indicative of this understanding by the applicant. One complete specimen of the device, for which approval is desired, shall be sent to the Central Experiment Station. On receipt of this application, fee, descriptive material, test data, and specimen to be tested, the manufacturer will be notified by the Bureau of its action on the application, the material required for test, and any additional information specifications that are deemed necessary. (c) Fees.

1. Types A or AE supplied-air respirators (complete) __

(i) Blower, single outlet_

(ii) Each hand-operated blower
outlet more than one (at

time of blower testing) -

(iii) Each motor-operated blower
outlet more than one (at
time of blower testing).

or

$675 220

20

(iv) Air-supply line (hose)

40 240

(v) Body harness_.

75

(vi) Respiratory-inlet

covering

175

$440 155 65

covering

175

(facepiece)

2. Types B or BE supplied-air respirators (complete).

(i) Air-supply line (hose)

(ii) Body harness.

3. Types C or CE supplied-air respira

tors, continuous-flow class

(iii) Respiratory-inlet

(facepiece)

7. Fees for tests of unusually complicated apparatus, for unusual tests or tests not included in this list, or for tests required for extensions of approval, will be based on the actual costs of testing, which will be determined in advance by the Bureau. The applicant will be notified accordingly, and the fee shall be paid before the tests are begun.

NOTE: If a respirator fails to pass any of the required tests and the applicant notifies the Bureau to terminate further investigation or testing, the Bureau will return to the applicant any part of the fee not applied to its compensation for services. If the respirator is resubmitted for testing and approval after correcting the deficiencies, the additional fee will be determined in advance by the Bureau and the applicant will be notified accordingly. Such fee shall be paid before tests are begun.

(d) Drawings and specifications required. (1) Respirators submitted for approval will not be inspected or tested until a complete description and two full sets of drawings showing all the details of construction have been delivered to the Central Experiment Station, Bureau of Mines, 4800 Forbes Avenue, Pittsburgh, Pennsylvania, 15213.

(2) The Bureau of Mines will not be responsible for any disclosures of ideas, principles, or patentable features because, under the terms of the application for tests, it is understood that the device is ready for release to public market. Caution will be exercised to prevent disclosure of details of the device to the public during approval testing.

Το

(e) Control-test requirements. maintain the quality of protection equal to that required by this part, the manufacturer must maintain adequate control of the production of the device and make tests of assembled devices to insure the fit of parts, freedom from air leakage, and general suitability. Each application for permissibility tests shall be accompanied by a statement showing the nature, adequacy, and continuity of the control provided by the applicant. Upon request of the Bureau, the applicant shall grant permission for a representative of the Bureau to inspect the control-test equipment and control-test records and to interview the personnel conducting the control tests. Tests for approval will be made only after the Bureau is satisfied that such control is ef

fective, and approvals once granted will remain in force only while the control is sustained.

(f) Material required for approval testing. The number of complete respirators and replacement parts required will depend on the type and design of the device. After application for test is received, the applicant will be notified concerning the material that it will be necessary for him to submit. All materials for tests shall be delivered gratis, with transportation charges prepaid by the applicant to the Central Experiment Station, Bureau of Mines, 4800 Forbes Avenue, Pittsburgh, Pennsylvania, 15213. The Bureau of Mines may retain as its own property any or all material submitted by the applicant that may be required for record. Material not required for record will be available to the applicant and will be returned at his expense on shipping instructions made in writing to the Central Experiment Station.

(g) Where investigations will be conducted. All investigations are conducted at the Bureau of Mines Central Experiment Station, 4800 Forbes Avenue, Pittsburgh, Pennsylvania, 15213.

(h) Date for conducting tests. The tests will be made in the order of fulfillment of pretest conditions. The applicant will be notified of the date on which tests will be begun. If a device fails to meet any of the requirements it shall lose its order of precedence. Tests will

be resumed following completion of other approval work which is in progress at the time both the request and the material for retesting are received. Exceptions may be made only for minor tests and inspections which may be performed simultaneously with other work in the laboratory.

(i) Observers at formal investigations and demonstrations. No one shall be present during any part of the formal investigation conducted by the Bureau which leads to approval for permissibility except the necessary Government personnel, representatives of the applicant, and such other persons as may be mutually agreed upon by the applicant and the Bureau. Upon granting approval for permissibility, the Bureau will announce that such approval has been granted to the device and may thereafter conduct, from time to time in its discretion, public demonstrations of the tests conducted on the approved device.

Those who attend any part of the investigation, or any public demonstration, shall be present solely as observers; the conduct of the investigation and of any public demonstration shall be controlled wholly by the Bureau's personnel. Results of chemical analyses of materials and all information contained in the drawings, specifications, and instructions shall be deemed confidential and their disclosure will be appropriately safeguarded by the Bureau.

[Sched. 19B, 20 F.R. 2564, Apr. 19, 1955; 20 F.R. 6552, Sept. 7, 1955, as amended at 30 F.R. 3753, Mar. 23, 1965]

§ 12.5

Requirements for Bureau of Mines approval.

To obtain the approval of the Bureau of Mines, a supplied-air respirator must pass the following inspection and tests:

(a) Container and markings. (1) If deemed necessary for the protection, proper maintenance, and storage of the respirator, a substantial and durable container may be required.

(2) Each respirator and required container shall be marked distinctly with the name of the manufacturer; the type of device, such as "Type A supplied-air respirator"; and the name, letter, or number by which the device is designated for trade purposes.

(b) Materials. (1) The respirator must be constructed in all its parts of materials which are suitable for the purpose they must serve; this applies to the fabric, rubber, metal, and other parts. All parts (especially rubber) that come into contact with the skin must be of nonirritating composition. All materials used in the construction of respiratoryinlet coverings and hose shall be of a nature that will withstand disinfection by methods recommended by the manufacturer and approved by the Bureau of Mines. These approved methods for disinfection shall be described in the instructions for use of the device as supplied by the manufacturer.

(2) Metal parts of Type A and Type B supplied-air respirators (except those parts that remain in uncontaminated air) should be of such composition or structure as to minimize the possibility of ignition of flammable atmospheres by sparks.

(c) Design and construction. Excellence of design, mechanical construction, durability, and workmanship will be con

sidered with regard to the safety of the wearer, the freedom of his movements, his range and clearness of vision, the fit of the respiratory-inlet covering, and the comfort afforded under all conditions of use. The ease with which parts of necessarily short life or period of use may be replaced by new or reconditioned parts, and the tightness of the whole apparatus, with a view to insuring the wearer against leaks of contaminated air both before and after such changes have been made, will also be considered.

(d) General requirements. (1) Each supplied-air respirator, when supplied with respirable air, must protect the wearer in the particular kinds of atmospheres for which it is approved. The Types A and AE supplied-air respirators may be approved for respiratory protection in essentially any atmosphere. The other types of supplied-air respirators may be approved for protection in any atmosphere that is not immediately dangerous to life or from which the wearer could escape without the aid of the device. These devices are approved only when used with respirable air and at the pressures and quantities required.

(2) The main parts of supplied-air respirators are as follows: Air-supply device (except Types B and BE); airsupply line; harness; and respiratoryinlet covering. Since the types AE, BE, and CE respirators for abrasive blasting differ from the corresponding suppliedair respirators only in the kind of respiratory-inlet covering, special requirements for the parts of these respirators are given only in the section on respiratory-inlet covering.

(3) The requirements for the complete respirators of the various types are grouped 'wherever possible.

(e) Requirements and tests for airsupply device. (1) Type A supplied-air respirator (hose mask). (i) Each Type A supplied-air respirator shall be provided with a hand-operated or motordriven air blower. No multiple system, whereby more than one user is supplied by one blower, will be approved unless each hose line is connected directly to a manifold at the blower. The blower shall permit free entrance of air to the hose when the blower is not operated, and it shall deliver the amount of air hereinafter specified with either direction of rotation, except when the construction of the blower is such that it

cannot be operated in other than a specific direction for delivering the required amount of air.

(ii) A hand-operated blower will be tested by attaching it to a mechanical drive and operating it continuously 6 to 8 hours daily for a total of 100 hours at the speed required to deliver 50 liters of air per minute through each respirator, when assembled with the kind and maximum length of hose for which the device is to be approved, connected to each blower or manifold outlet designed for hose connections. The blower shall operate throughout the period without failure or indication of excessive wear of bearings or other working parts. The crank speed of a hand-operated blower shall not exceed 50 revolutions per minute to deliver the required 50 liters of air per minute to each facepiece. For a hand-operated blower the power required to deliver 50 liters of air per minute to each wearer through the maximum length of hose shall not exceed one-fiftieth horsepower, and the torque shall not exceed a force of 5 pounds on an 8-inch crank. The torque and power shall be measured as hereinafter provided.

(iii) A motor-operated blower shall be tested by operating it continuously at its specified running speed 6 to 8 hours daily for a total of 100 hours when assembled with the kind and maximum length of hose for which the device is to be approved and when connected to each blower or manifold outlet designed for hose connections. The blower shall operate throughout the period without failure or indication of excessive wear of bearings or other working parts. The connection between the motor and the blower shall be so constructed that the motor is disengaged automatically from the blower when the blower is operated by hand.

(iv) When a blower, which ordinarily is motor driven, is operated by hand, the power required to deliver 50 liters of air per minute to each wearer through the maximum length of hose shall not exceed one-fiftieth horsepower, and the torque shall not exceed a force of 5 pounds on an 8-inch crank. The torque and power shall be measured as hereinafter provided.

(v) When assembled with the facepiece and 50 feet of the hose for which it is to be approved and when connected to one outlet, with all other outlets

or slightly above the speed at which the power measurement is to be made. The blower is then permitted to assume constant speed, and then as the first mark on the wire leaves the drum a stopwatch is started. The watch is stopped when the second mark leaves the drum. From these data the foot-pounds per minute and the torque may be calculated readily.

(2) Type B supplied-air respirator. No Type B supplied-air respirator will be approved for use with a blower or for connection to an air-supply device at positive pressures. Instead, the inlet to the hose shall have a terminal fitting or chamber which provides for drawing the air through a suitable arrangement that will remove material larger than 0.149 mm. in diameter (149 microns, 100-mesh, U. S. standard sieve of corrosion resisting material). This terminal fitting shall be provided also with means for fastening or anchoring it to a fixed position in a zone of respirable air.

(3) Type C supplied-air respirators, continuous-flow class. The air-supply device is the responsibility of the user. The respirators are approved, however, only when used with respirable air and at the pressures and quantities required. The pressure at the hose connection to the blower or manifold shall not exceed 125 pounds per square inch gage. If, however, the pressure at any point in the supply system exceeds 125 pounds per square inch gage, the user must provide a pressure-release mechanism that will prevent the pressure at the hose connection from exceeding 125 pounds per square inch gage under any conditions.

(4) Type C supplied-air respirators, demand and pressure-demand classes. (i) The air supply is the responsibility of the user. It may be an air-compressing system or a reservoir of compressed air. The respirator is approved, however, only when used with respirable air at the pressures and quantities required. (ii) The manufacturer may specify the range of air pressure at the point of attachment of the air-supply hose to the air-supply system, and the range of hose length for the respirator. For example, he might specify that the respirator be used with compressed air at pressures ranging from 40 to 80 pounds per square inch with from 15 to 250 feet of air-supply hose. The specified air pressure at the point of attachment of the hose to the air-supply system shall not exceed 125 pounds per square inch gage. Should the pressure in the air-supply system exceed this value, the user must provide a pressure-reducing and pressure-release mechanism that will prevent the pressure at this point from exceeding this value. However, the pressure-release mechanism may be set to operate at a pressure not more than 20 percent above the manufacturer's highest specified pressure. For example, if the highest specified pressure is 80 or 125 pounds per square inch, the pressurerelease mechanism would be set to operate at 96 or 150 pounds per square inch, respectively.

(f) Requirements and tests for airsupply lines. The requirements and tests of the air-supply lines are given in table 1 of this section.